The present invention relates to an infusion set, in particular to a device for inserting a cannula into tissue, for example skin tissue, fatty tissue or muscle tissue, and to a device for supplying a liquid via the cannula into the tissue.
A device for inserting a catheter comprising a needle is known from EP 0 451 040 A1, wherein a cover is provided which may be pushed together over the needle. The catheter can thus be inadvertently removed even by small drag forces acting on the catheter, and lies open, relatively unprotected, at the injection point; see FIG. 1 in EP 0 451 040 A1.
EP 0 290 176 A1 discloses a device for inserting a cannula comprising a needle, wherein the needle has to be pressed against a spring when being inserted and is retracted by the spring force into a casing after the insertion process. Here, too, the cannula is relatively unprotected once inserted, and can easily be inadvertently removed.
A device for subcutaneously supplying a medicine is known from EP 0 615 768 B1. A cannula comprising a needle is inserted, wherein at the same time as the cannula is inserted, an arrangement connected fixedly to the cannula and having an adhesive underside is applied to the skin, which makes the injection process, which is often unpleasant for the user, additionally difficult.
In the known devices, the cannula is either relatively unprotected against being unintentionally removed, a drag force acts on the cannula inserted into the tissue even as the needle is removed from the cannula, or an additional device has to be moved together with the cannula during the injection process, which makes positioning it exactly difficult.